Pinterest's traffic was up almost 50% from February to January
2012 and Pinterest's unique visitors increased from 11
million to 17.8 million. One week during January yielded 21.5
million Pinterest visits, which is 30 times what its traffic was
six months prior.

People are still most engaged on Facebook, spending an average of
405 minutes per month on it. They're spending about 89
minutes per month on Pinterest.

But all you really need to know about Pinterest is in the chart
below. Here's what its total visits look like since last year --
the past three months are nearly a vertical line.